docs: def eval_stats(values, mode):
      '''Extract a summary statistic from an array of list of values
  
      Parameters:
          values: numpy array of values
          mode: summary stat to extract. One of ['min', 'max', 'median', 'mean', 'std', 'raw']
  
      Note: fails silently if values is empty, and None is returned
      '''
      if mode == 'raw':
          return values.tolist()
      if mode == 'total':
          mode = 'sum'
  
      try:
          return getattr(np, mode)(values, axis=0)
      except ValueError:
          pass
  
      return None